Hello,
For more than two years now no one can find out what's wrong with rear suspension of my x308.

Symptoms:
1. Rear suspension Very unstable (i mean very!) on bumps (especially on higher speeds)
2. Soft (not metal to metal) rattle comes from rear left and right while driving on even slightly rough road. Sounds like some tools are rattling inside boot/trunk

Official Jaguar repair service in my country found - nothing.
Official government Vehicle/MOT inspection found - nothing
Other 4 independent auro repair shops found - nothing.


Any thoughts?

 

Well, here's a place to start for schematic details and other references, use the site search...JagRepair.com - Jaguar Repair Information Resource ....this is one of the pdf's...http://www.jagrepair.com/images/Intr...al-10-3-02.pdf

 

Hi,
Thank You for suggestion.
Everything You mentioned here is already checked!

 

What about the lower hub carrier bearing preload? Have had but it passed wheel alignments but messed with handling and had metal clunks with hub hitting lower arm. PO poor repair...

 

Recently inspected wheel bearings and only relubricated because they were fine.
As a preventive measure i changed the pivot pin bearings, but they were fine also.

 

Have you checked the pinion to see if there is play in the gears or pinion itself and the fluid level?

 

Do you mean differential?
There is some play but my mechanic says its within norms.
Diff oil replaced 15000km/10000miles ago. Old fluid came out clean.

 

What kind of tires do you have, and what are the pressures?

 

235/50 R17 M+S.
2.30 bar

I did the tyre change during those 2 years.

 

Yes, the differential was what I was meaning for the fluid check.
I'm not trying to harp on this, but here is a link regarding the disassembly and replacement of the rear shocks and bushings for what I asked about prior. The fact you have a clunking noise and uncontrolled sway just screams shock assembly. I just want to be sure they took the time to be able to find the issue once you see how much is involved. You don't need to break it down to check it, but isn't the easiest check.
http://jaguar.blackonyx.net/tech/rearshocks.pdf

 

I went through almost this exact same thing with my SVP so maybe I can give some experience.

Anything over 25mph and a rough road or bumps and the car felt like it was going to shake apart. Single pot hole or bump would send a sideways shimmy through the whole car like the tail was wagging the dog. Scary feeling. I also had a number of noises and clunks I could hear if I found something to drive alongside.

I have replaced almost every component on the rear end of mine and can take an the back end out with my eyes closed.

1. Check the rear shocks and the upper shock bushings. Shocks too soft/worn and bad shims/upper bushings gives too much play in the rear end. After replacing and double checking the towers were bolted into place tightly the shake went away. I also replaced the A-frame bushings also which eliminated any left over shake.

2. I had some louder "heaver" banging noises that went away by adding some nylon washers to the mounts on the monostrut. I still seem to have a few random noises in back. Once the shocks/bushings have been checked it is likely part or parts of the parking brake and dust shield--depending on types of sound.

It seemed all of my issues were a "sum of parts" in that no bushing or mount was that bad but combined they gave too much play. All the movement lead to the knocking and banging.

Worn shocks
Bad upper bushings and shim
Shock towers tightened down
A-Frame mounts
Play in Monostrut mounts

Hope some of that helps.

 

I had rear shocks removed for inspection, replaced lower bushings (just in case), the upper ones looked OK.
The shocks were checked by hand, they were sliding out and in smoothly with resistance.
A-frame bushing was checked, double checked, looked OK.

I replaced monostrut mounts and all other bushings that holds differential a few weeks ago hoping that they are causing the problem, but the old ones seemed to be pretty OK. My mechanic did an enormous work for that.

My intuition tells me that it can be shocks causing the noise by some mistyrious undetectable way

 

Dang, so since you went through the other checks, it would have to be presumed that the universals were also inspected?
I'm going to sleep on it and see if something comes of it. Like maybe subframe connectors or such?

 

U-joints?
Yes, i replaced them all!

 

You didn't mention the spring spacer and upper isolators but i'll assume those are in good condition. I am not a fan of tossing parts at a car but for a couple hundred bucks I'd try for new rear shocks. Couldn't hurt

During the time I was replacing everything in the backend of mine I also replaced the front subframe V-mounts as they were looking weak. I'm not sure how much of a difference it made but sure it helped a bit.

 

Ok, lets check some things, please review this and tell us what you can. Also, when was the last alignment done and when was the last time the car operated without this issue?

 

Hello
After I discovered the source of the noise at the front of the car (electronic dampers in soft mode it clicks, if you remove the fuse from the suspension system and shock absorbers are in hard mode, noise stops), I left with a noise on the left rear top damper . Mention that the damper bushes are new. I removed damper twice to identify noise. The only thing I should do is to dismantle again and check damper position 24 in the photo.

Tip: For those who have CATS system, first thing you should do is to take off the fuse from suspension system, if the dampers are strengthened and the noise disappears. Absorbers no longer works well.
I will follow with interest the results of other fellow forum
I want to remove this noise

 

Hi, mine's without CATS.

 

Without CATS it sounds like dead dampers.

You or anyone else happen to know the stud-bolt and nut size/pattern for the rear shock towers that bolt into the frame?


I recall mine were rusted, worn and generally very difficult to remove. It could be an area of extra play on my car and maybe yours as well. I am planning on replacing mine (8 total I think) just to make sure that part of the suspension is tight and not causing issue.

 

I would be looking closer at the wheel bearings, the axle in reality is the upper control arm(wishbone) which means the "U" joints and wheel bearings become inner and outer control arm bushes - I have seen loose wheel bearings cause wheel alignment problems, and strange sounds.
MHO - you and a huge number of other people have looked at it, and overlooked something - I didn't notice exhaust anywhere, but you must have checked that also.
Cheers and good luck
DC